In our previous work, we developed four major bioinformatics tools/databases: (1) the web-based ANOVA-FDR software to provide user-friendly microarray data analysis (http://lgsun.grc.nia.nih.gov/ANOVA/); (2) an algorithm and a fully-automated computational pipeline for transcript assembly from expressed sequences aligned to the mouse genome; (3) a web-based browser to visualize all transcripts and alternative spliced forms of mouse genes (NIA Mouse Gene Index: http://lgsun.grc.nia.nih.gov/geneindex/mm9/); (4) a web-based database and tool to visualize and map the transcription factor binding sites of the mouse genome (CisView: http://lgsun.grc.nia.nih.gov/geneindex/mm6/cisview.html); and (5) a web-based tool to identify consensus sequence motifs based on the genome-wide chromatin-immunoprecipitation coupled with sequencing (ChIP-Seq) method (CisFinder: http: http://lgsun.grc.nia.nih.gov/CisFinder/). During the last year, we have been working on maintaining and updating these bioinformatics resources. We have also developed a new algorithm to simulate the gene expression regulated by two competing transcription factors.